1. Field of the Invention
The present invention relates to a recording apparatus for recording an image and the like on a recording medium (e.g., recording paper). In particular, the present invention relates to a recording apparatus for recording by discharging ink droplets from a recording head detachably attached on a carriage which is movable along the recording medium.
2. Description of the Related Art
Recently, as personal computers and digital cameras have become widespread, the handleability of image information has been increased, thus increasing the demand for uncomplicated recording apparatuses used to output such image information. Among various recording methods used in such recording apparatuses, inkjet recording is known as a recording method that allows a relatively small recording apparatus and achieves inexpensive and high-definition recording.
In a recording apparatus using such an inkjet recording method, an inkjet head cartridge, in which a recording head having a nozzle portion composed of several tens to several hundreds of discharge openings and an ink tank for supplying ink to the recording head are integrally formed with each other, is detachably attached to a carriage. The carriage is connected to a part of a driving belt for transmitting a driving force of a carriage driving motor so as to be movable. The movement of the carriage moves the inkjet head cartridge along a platen arranged opposite a discharge surface. During the movement, the inkjet head cartridge reciprocates (scans) along the full width of a recording medium transported onto the platen to perform recording. The recording medium is conveyed a predetermined distance determined according to the pitch of the nozzle portion by a conveying unit with every scanning of the carriage. Repeating such a scanning of the carriage and a conveyance of the recording paper completes recording on the entire area of the recording medium.
Some inkjet recording apparatuses using a recording unit (e.g., recording head or inkjet head cartridge) detachably attached on a carriage, when ink within an ink tank runs out or the recording head is broken, can easily return to a state capable of recording by replacing the recording unit with a new one.
Furthermore, some inkjet recording apparatuses can output (record) a photographic image with good photographic quality by including high-density and high-quality discharge openings (nozzles) for discharging ink on, for example, a recording head integrally formed with an inkjet head cartridge. Moreover, some inkjet recording apparatuses have become widely available in which the speed of an image output is further enhanced by a long recording head having an increased number of nozzles.
Some conventional inkjet recording apparatuses typically eliminate clogging (e.g., paper dust or thickened ink within nozzles) by moving a recording head to a preliminary discharge position after recovery processing performed by a recovery unit or when a carriage scans during recording and then performing preliminary discharge predetermined times in order to maintain the quality of recording by the recording head. At the preliminary discharge position, a waste-ink absorber is arranged opposite a nozzle surface so that the waste-ink absorber absorbs ink droplets dropped by performing preliminary discharge toward a preliminary-discharge receiving opening.
The conventional structure has a problem of accumulation of crud inside the apparatus caused by ink mist splashing off the preliminary-discharge receiving opening and ink mist flowing and spreading from between the preliminary discharge receiving opening and the waste-ink absorber and crud inside the apparatus caused by ink mist generated while a recording paper is recorded on.
As one approach to address the problem, a structure that suppresses the generation of ink mist by providing a waste-ink absorber and a preliminary discharge receiving mechanism that can control the flow of ink mist is discussed in U.S. Pat. No. 6,565,189.
However, the conventional preliminary discharge receiving mechanism discussed in U.S. Pat. No. 6,565,189 may have a problem of a significantly large unevenness of obtained advantageous effects because the control of the flow of ink mist depends on the characteristics of a material of the waste-ink absorber and the acuteness of an incident angle of an ink droplet against the surface of the waste-ink absorber. Additionally, this traditional structure may have the drawback of a high cost of manufacturing because the waste-ink absorber is limited to a significantly narrow range of materials.
Furthermore, the conventional inkjet recording apparatus described above is prone to generate ink mist because the apparatus absorbs ink mist due to a preliminary-discharge receiving opening arranged in a platen, in which the gap between the platen and a recording head is relatively large, and therefore, the travel distance of ink droplets through the air from a nozzle portion to the preliminary-discharge receiving opening is increased.